Conveyor dishwashers (conveyor warewashers) are used in the commercial sector. In contrast to domestic dishwashers, in which the washware to be cleaned remains stationary in the machine during cleaning, in conveyor dishwashers the washware is conveyed through various treatment zones of the machine.
In the case of conveyor dishwashers, the washware, for example dishes, pots, glasses, cutlery and other articles which are to be cleaned, is conveyed through a plurality of treatment zones, for example prewash zone(s), main wash zone(s), postwash or pre-rinse zone(s), final-rinse zone(s) and drying zone(s). A conveyor apparatus which generally has compartments for accommodating washware is used to convey washware in a conveying direction through the conveyor dishwasher. In the case of a flight-type dishwasher, the compartments can be formed by supporting fingers on a conveyor belt of the conveyor apparatus. In the case of rack conveyor dishwashers, dish racks in which compartments can be formed in order to accommodate the washware to be treated serve as the conveyor apparatus. It is feasible here for the dish racks to be conveyed through the rack conveyor dishwasher by a conveying device.
U.S. Pat. No. 6,530,996 B2 describes a rack conveyor dishwasher in which the washware to be treated is fed to the respective treatment zones in a state in which it is pre-sorted in dish racks. This conveyor dishwasher which is known from the prior art is provided with sensors with can be used to detect an identifying feature which is fitted on the dish rack and indicates the type of washware accommodated in the dish rack. A suitable washing and/or rinsing programme of the rack conveyor dishwasher can be selected as a function of the detected identifying feature.
DE 196 08 030 C1 discloses a conveyor dishwasher in which, depending on the type and degree of soiling of the washware to be cleaned in the individual treatment zones of the conveyor dishwasher, additional spray systems are switched on or off in order to change the size of the action section in the treatment zones.
It is already known from DE 10 2005 021 101 A1 to switch on or switch off additional spray nozzles in a conveyor dishwasher as a function of the conveying speed in the final rinse zone, as a result of which the consumption of final rinse liquid during operation can be reduced. Sensors are provided at the entrance of the conveyor dishwasher in order to detect washware. The conveying speed is automatically reduced when the quantity of washware entering the conveyor dishwasher decreases.
A similar conveyor dishwasher is also known from DE 695 25 337 T2. In this prior art document, a sensor is used to detect the presence of washware to be treated. If no washware is present, washing operation is interrupted until washware passes the sensor again.
Finally, DE 196 08 036 C5 discloses a further conveyor dishwasher in which the quantity of final rinse liquid sprayed in the final rinse zone per unit time is changed as a function of the conveying speed and as a function of the respective rinsing programme. The quantity of fresh water sprayed during final rinsing and the quantity of rinse aid used for final rinsing are in each case coupled to the conveying speed and to the respective rinsing programme and are changed as a function of these.